We would be mad to adopt a system that is less fair than the one we already
have, writes Boris Johnson.

I hope I will be forgiven if I indulge in a few tasteless comparisons between the crazed and increasingly blood-soaked tyrant Muammar al-Gaddafi and former UK Prime Minister Gordon Brown. After all, the two men look vaguely similar; they both appear to believe in the efficacy of Grecian 2000; they both favour long and rambling speeches on socialist economic and political theory, with Col Gaddafi's efforts perhaps having a slight edge in logic and coherence. And even if most fair-minded people would say that they were very different political personalities, there is one essential point in common between Tripoli in 2011 and the dying months of the last Labour government.

When a regime has been in power too long, when it has fatally exhausted the patience of the people, and when oblivion finally beckons – I am afraid that across the world you can rely on the leaders of that regime to act solely in the interests of self-preservation, and not in the interests of the electorate.

That is why Labour continued to spend and borrow and bribe right up to the wire, desperately hoping to hang on, and racking up such huge debts that Treasury Minister Liam Byrne left a note to his successor gloating that there was "no more money left". And that was why in February last year the doomed Gordon Brown performed his breath-takingly cynical U-turn, announcing after a lifetime's opposition that he was a convert to the Alternative Vote system for parliamentary elections. Why did he do it?

What was behind this mad last roll of the dice? It is a bizarre feature of the AV referendum that it was actually proposed by neither of the parties who won the 2010 election, and who now form the government, but emerged as a last gasp from the bunker of the man who lost.

It seems unlikely that in the next few weeks the AV campaign will mobilise the masses in the way that we have seen in North Africa. I don't expect that the television news will be cutting to Parliament Square, to find John Simpson joining hordes of chanting pro-AV supporters as they prepare to face the reactionary camel-charges of those who believe in first-past-the-post.

Alas, the whole thing threatens to be a bit of a damp squib. Which is a shame, because the more closely people focus on what is being put to the people on May 5, the more clearly they should see that this is a gigantic fraud. In case you haven't been paying attention, the idea is that instead of just voting for the candidate you want, you can express a series of preferences – 1, 2, 3, and so on – so that the recipient of your second-preference vote might edge ahead if your first preference candidate is knocked out.

It is the system, I may as well admit, that is used in London mayoral elections. It may be just about tolerable there; but I can see no case whatever for introducing it across the country.

Why on earth are we contemplating this change for Westminster elections?

People say that it will boost minor parties who don't normally get a look in; and yes, it is indeed true that if you vote for the BNP you will effectively have two votes – one for the BNP and one for whomsoever you place second. Is that such a great thing?

Then we are told that it will somehow make MPs more accountable and more diligent, because they will all be obliged to get the combined first and second-preference support of 50 per cent of the voters. Well, if the proponents of the change looked at UK election results they would see there are large numbers of seats where the incumbents already receive at least 50 per cent of the votes. They tend to be seats with relatively small numbers of constituents in urban areas – that's right; they tend to be Labour seats, where the population has tended to shrink over the years as people sensibly flee areas represented by Labour MPs.

Where is the evidence that these MPs will become more diligent, more conscientious, more in touch with their electorate through the introduction of AV? It is complete tripe, and the same goes, of course, for occupants of all the very safe Conservative seats.

If you are sitting on more than 50 per cent of the vote, you are not even affected. Then I suppose there are still some people who have become hopelessly confused, and think that AV is something to do with "fair votes", and proportional representation. It is not. It would do nothing whatever to address the problem of Labour under-representation in the South East and Tory under-representation in the north, Scotland and Wales. When Roy Jenkins was asked by Tony Blair to report on voting reform, he wrote that AV should be ruled out because it would actually make the system less proportional and less fair.

Remember Blair's massive victory of 1997, when he got 419 seats with 43 per cent of the vote? Under the AV system he would have got 445 seats, and the Tories (who won 30 per cent of the vote) would have been reduced to 70 seats instead of 165. Indeed, if AV had been in force at the last election, the Tories would have got 281 rather than 306 seats – and Labour would have been up four, on 258. And that, of course, is why Gordon Brown announced his panic-stricken death-bed conversion – in the deluded hope of changing the odds and gerrymandering the system.

Nick Clegg himself was right to oppose AV before the election, and he should stick to his guns. First-past-the-post has served this country well, and served dozens of other countries well. We would be mad to go to a great deal of trouble and expense to adopt a system that is less fair than the one we have.

It is bonkers to be pursuing the last manoeuvre of a cornered Gordon Brown. By all means let us have a referendum – the one we were promised, on the Lisbon EU Treaty. Have you noticed the EU policy on North Africa? Have you heard much from Baroness Ashton? Shouldn't we have a vote on all that?